check for curl headers in configure script
check for curl headers in configure script

seem-sky/restclient-cpp,69736c616d/restclient-cpp,benjam60/restclient-cpp,seem-sky/restclient-cpp,embeddedmz/restclient-cpp,embeddedmz/restclient-cpp,mrtazz/restclient-cpp,mrtazz/restclient-cpp,69736c616d/restclient-cpp,benjam60/restclient-cpp,69736c616d/restclient-cpp,seem-sky/restclient-cpp,benjam60/restclient-cpp,69736c616d/restclient-cpp,benjam60/restclient-cpp,seem-sky/restclient-cpp